Further development of a reactivated preparation of bull spermatozoa. Influence of stimulators (adrenaline and analogues) will be investigated. Effects of electrical stimulation dependent on additions to the medium will be worked out. The function of the coarse fibers will be investigated using demembranated and desheathed sperms. The mechanism for coordination of the contractility will be investigated theoretically and experimentally. BIBLIOGRAPHIC REFERENCES: Effects of direct current injection on the activity of bull spermatozoa. Peter O'Day, R. Rikmenspoel and C.B. Lindemann, Biophys. J. 16, 119a, 1976. Partial inhibition of motility in reactivated bull sperm using NiCl2 and CuSO4. C.B. Lindemann and R. Rikmenspoel, Biophys. J. 16, 120a, 1976.